Electrically heated windows or the like



July 16, 1968 J. R. DAVY ETAL 3,392,759

ELECTRICALLY HEATED WINDOWS OR THE LIKE Filed Sept. 16, 1965 5 Sheets-Sheet 1 A/I/EIVTORS JOHN (ZUPE 'r oAvv,

ALEXANDEIZ, JAMES NAPIER. HOPE v:rcM-m AJHEKPATZKJA July 16, 1968 J. R. DAVY ETAL 3,392,759

ELECTRICALLY HEATED WINDOWS OR THE LIKE Filed Sept. 16, 1965 5 Sheets-Sheet 2 JOHN RUPERT bAv f ALEXANDER JAMES NAPIER. uope$ 3mm wea on-men July 16, 1968 J, v ETAL 3,392,759

ELECTRICALLY HEATED WINDOWS OR THE LIKE Filed Sept. 16, 1965 5 Sheets-Sheet 5 MlVE/VTOA J'OHN RUPERT DAVY, ALEXANDER JAMES NAPIER. HOPE JOHN A KIRKPAW CK Wiasm, m

Arm/ m July 16, 1968 J. R. DAVY ETAL 3,392,759

ELECTRICALLY HEATED WINDOWS OR THE LIKE Filed Sept. 16, 1965 5 Sheets-Sheet 5 y sou-m RUPERT bwvf ALEXANDER. JAMES NAPIER. HOPE JOHN A. "axon-mm i ")ascvL,

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United States Patent ABSTRACT OF THE DISCLOSURE- Apparatus for use in the manufacture of electrically heated windows having a series of spaced side-by-side lengths of fine, crimped, electricity-conducting wire extending therethrough, comprising a frame to receive wire lengths across the space thereof, a carriage bridging the frame spaced longitudinally of the frame and mounted at its ends for reciprocation transversely of the frame,

and a crimping head on the carriage including a pair of v co-operating rotary toothed wheels adapted to crimp wire from a source on the head and lay lengths of crimped wire across the frame, space reciprocation of the carriage, said head being longitudinally movable on the carriage following each operating stroke so that the crimped wire lengths are spaced side-by-side on the frame, the apparatus being manually or alternatively automatically operable.

This invention relates to apparatus for use in the manufacture of electrically heated windows of the kind having a plurality of spaced side-by-side lengths of fine, opaque electricity-conducting material extending therethrough.

These windows are normally of sandwich structure comprising two or more layers of light transmitting material with crimped wires sandiched therebetween.

'Heretofore, these windows have usually been manufactured by first crimping the wire and then manually laying the crimped wire on a first layer of light transmitting material and sandwiching the wire in the structure by securing a second layer of light transmitting material to the first layer.

An object of the invention is to provide apparatus which facilitates the manufacture of windows of the kind aforesaid.

Embodiments of the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which FIG. 1 is a perspective view of a manually operable machine for crimping and laying wire for the window,

FIG. 2 is a detail view showing the crimping wheels and the crimped wire lengths.

FIGS. 3a and 3b are a sectional end view of the gear box of an automatic wire crimping and laying machine,

FIG. 4 is a sectional detail view on the line IV-IV of FIG. 3, and

FIG. 5 is a sectional detail view of the crimping head of the automatic machine.

An electrically heated window of the aforesaid kind is composed of a series of side-by-side generally parallel, regularly spaced lengths of crimped opaque, electricityconducting wire sandwiched between two sheets of glass which are secured together e.g. by a suitable cement. The wire is oxidised Nichrome of .000 nominal diameter, the crimping factor of the crimping gear was 1.02, and the spacing of the wire lengths is approximately 5 inch centres. The crimp is the same throughout the wire lengths and is of regular wave form, or alternatively of regular V form. The crimping of each wire length is out of phase with that of the immediately adjacent length or lengths so 3,392,759 Patented July 16, 1968 that each inter-wire space varies along its length and also the inter-wire spaces vary from space to space transversely of the wires. It is found that by introducing irregularity in the inter-wire spaces transversely and/or longitudinally of the wires, the usual diffraction effect at the wires is obviated or mitigated.

The irregularity in the spacing may be introduced in any other convenient way e.g. byirregular crimping of some or all of the wires, by stretching some or all of the identically crimped lengths in varying degree to destroy the identity between the lengths, or by laying the crimped wire lengths convergently and/or divergently.

In making the window, the crimped wire lengths are laid acrossa rectangular frame, being anchored at their ends by any suitable means to opposite sides of the frame which with the wirelengths thereon is placed over a glass sheet so that the wire lengths lie on the sheet. A second glass sheet is thenplaced on the supported -wire lengths to sandwich them between the glass sheets which are secured together, say by a suitable cement. In this way the difficult and tedious work of laying the wire lengths sideby-side directly on to a glass sheet is avoided.

Referring to FIGS. 1 and 2, a machine for use in crimping and laying the wire includes a rectangular frame 1 with a pair of opposite side bars 2 and 3 to receive the ends of the wire lengths which extend across the frame opening. A carriage 4, including a longitudinal beam 5 and end supports 6 and 7, bridges the frame 1 from end to end thereof and is reciprocable transversely of the frame, the end supports being slidingly guided in fixed end blocks 8 and 9. A crimping head 10' is mounted on the carriage 4 for movement to and fro along the carriage, being supported by rollers 11 running on top of the beam 5, and slidingly engaging a rotary driving shaft 12 mounted in the end supports 6 and 7. The shaft 12 is manually rotatable and drives, through toothed wheels 13, end pinions 14 which engage racks 15 to cause transverse movement of the carriage. The shaft 12 also drives the crimping wheels 16 through bevel wheels 17 and meshing pinions 18 which are integral and coaxial with the crimping wheels, the latter being slightly spaced apart to provide a wave-form crimping passage 19 between the opposed wheel teeth (FIG. 2). The crimping head 10 also carries a wire supply bobbin (not shown) which feeds straight wire horizontally to the crimping wheel 16. In use of the machine, the carriage 4 is moved forwards and the crimping head 10 to one end of the carriage. The Wire end is then threaded between the crimping wheels 16 and secured to the front 2. The carriage 4 is then moved rearwards to cause simultaneous crimping of a wire length and laying of same across the frame opening. The crimped wire is then severed at the rear end and secured to the rear bar 3. The crimping head 10 is then moved along the carriage 4 and the operation is repeated to provide a series of spaced side-'by-side generally parallel lengths 20 of crimped wire (FIG. 2) with the wave-form crimps of each wire length out of phase with those of the next adjacent length or lengths. The frame with the crimped wire lengths thereon is removed and deposited on a glass sheet so that the wire lengths rest on the sheet, and a second glass sheet is then deposited on the wire lengths and secured to the first glass sheet.

In an automatic version of said machine, the wire is crimped and laid during both strokes of each reciprocation of the carriage, and the crimping head is adjusted longitudinally at the end of each working stroke. Rows of pins on the frame bars receive the crimped wire which is thus looped around the pins and extends in a zig-zag path from side to side of the frame, with generally parallel lengths of crimped wire extending across the frame opening. Operation of the machine is effected through a gearbox (FIGS. 3a and 3b) which is mounted in an end support of the carriage and includes a transversely extending drive shaft 21 axially reciprocable in the support and with its ends projecting from opposite sides of the support to engage fixed stops (not shown) at the ends of the car riages working strokes. To operate the machine, the shaft 21 is driven, e.g. by an electric motor, through gears 22. A unidirectional drive from the shaft 21 to the crimping wheels includes a pair of face clutches 23, 24 engageable alternately on movement of the shaft in either direction from a mid-or neutral position, pairs of toothed wheels 25, 26 which alternately drive a counter shaft 27, and bevel gearing 28 connecting the countershaft to a shaft 29 extending from end to end of the carriage. A reversible drive from the shaft 21 to the rack-engaging pinions on the sliding carriage includes a pair of face clutches 30, 31 alternately engageable on movement of the shaft in either direction from the midor neutral position and respectively driving a corresponding pair of bevel pinions 32, 33 meshing with a bevel wheel 34 which rotates a shaft extending from end to end of the carriage and carrying the rack-engaging pinions.

A nut on the crimping head engages a screw-threaded rod extending between the end supports of the carriage, and a drive to the nut operates at the end of each working stroke of the carriage to effect longitudinal adjustment of the crimping head on the carriage. The drive to the nut is unidirectional and extends from the shaft 21 through a pair of meshing toothed wheels 35, 35A to a parallel shaft 36 carrying the pin wheel 37, with pins 37A, of a maltese-cross type gear whereof a slotted wheel 38 is on a shaft 39 which drives, through toothed wheels 40, a parallel shaft 41 which in turn drives the nut through bevel gears 42. The toothed wheels 35, 35A have thereon elements of pairs of face clutch elements 43, 44, and are joined for sliding movement in unison on their shafts, being urged by a compression spring 45 to clutch-engaging position. Thus, the clutches 43, 44 are both engaged and the drive operative when the shaft 21 is in its midor neutral position, and axial movement of the shaft 21 in either direction disengages one or other of the clutches to disconnect the drive.

Clutch control mechanism for effecting movement of the shaft 21 to appropriate carriage-driving position following each adjustment of the crimping head consists of a two-armed lever 46 and a rotary cam 47 engaging one end of the lever to actuate same, the other end of the lever engaging a grooved collar on the shaft 21. The cam 47 is rotated unidirectionally by the pins 37A on the pin Wheel 37, the pin 50- acting on a slotted wheel 48 on a shaft 49 carrying the cam. Each rotation of the cam is through 180, and the cam is shaped so that successive rotations cause movement of the shaft 21 in opposite directions, and movement of the arm 46 to neutral position is permitted at the end of each working stroke of the carriage. A ball catch 51 co-operates with grooves in the shaft 21 to tend to retain the shaft in each control position.

In the crimping head, the crimping wheels 17 and 18 rotate on horizontal longitudinal axes (FIG. and are driven from the shaft 29 through a train of gear wheels including a pair of meshing wheels 17A, 18A coaxial and integral with the crimping wheels. The straight wire passes from a storage roll (not shown) downwards to the crimping wheels, and the crimped wire issues downwards between a pair of radiused guides 52 around one or other of which the wire passes in accordance with the direction of movement of the carriage. The pins 53 on each frame bar 54 are in two staggered rows, and each pin is notched at 53A and urged by a spring 55 to a low position in which the pins enlarged lower end 56 projects from the bottom of the bar. A slidingly supported wedge 57 actuated by the crimping head engages the end 56 of each pin in turn to raise the pin against spring action to a high position to receive in its notch the crimped wire from the head, each pin returning to its low position on withdrawal of the wedge, and the crimped wire loop being retained on the pin by the notch.

In operation of the machine, the carriage reciprocates and at each stroke a length of wire is crimped and layed across the frame. At the end of each carriage stroke, the shaft 21 is moved by a stop to'mid position in which the drives to the crimping wheels and carriage are disconnected and the drive to the maltose-cross typegear is engaged. The pin wheel of said gear has its pins so arranged as to make two adjustments in sequence, namely, adjustment of the crimping head to effect looping of the crimped wire around the pin, and adjustment of the clutch control mechanism to effect movement of the shaft 21 to a position for'reverse driving of the carriagez Thus, the machine crimps the wire and simultaneouslylays the crimped wire in a zig-zag path across the frame and around the pins on the frame bars. .With the zig-zag wire secured to the frame, the latter is removed from the machine and glass sheets applied to the wire lengths in the manner hereinbefore described, to form an electrically heated window. The machine in automatically laying the crimped wire in a zig-zag path, provides for random positioning of the crimps of each length in relation to the crimps of the next adjacent length, thereby ensuring that the crimps of adjacent lengths are out of phase.

We claim:

1. Apparatus for use in the manufacture of electrically heated windows having a series of spaced side-by-side lengths of fine, crimped electricity-conducting wire extending therethrough, comprising a frame to receive wire lengths across the space thereof, a carriage bridging the frame space longitudinally of the frame and mounted at its ends for reciprocation transversely of the frame, and a crimping head on the carriage including a pair of cooperating rotary toothed wheels adapted to crimp wire from a source on the head and lay lengths of crimped Wire across the frame space on reciprocation of the carriage, said head being longitudinally movable on the carriage following each operating stroke so that the crimped wire lengths are spaced side-by-side on the frame.

2. Apparatus according to claim 1, including a carriage drive, a crimping-Wheel drive, and a common driving shaft connected to both drives, so that on rotation of the driving shaft the crimping of the wire proceeds simultaneously with the laying of the crimped wire across the frame.

3. Apparatus according to claim 2, including rows of pins on opposite sides of the frame, clutch means in the carriage and crimping-wheel drives, a crimping-head drive connected to the driving shaft through clutch means, the driving shaft being axially reciproca-ble to actuate the clutch means of the several drives, clutch control means for effecting axial sliding of the driving shaft and including a drive operatively associated with the crimping-head drive, and stops engageable with the driving shaft ends to cause axial sliding of the shaft at the end of each stroke of the reciprocating carriage, the arrangement being such that with the driving shaft displaced axially in one direction from a mid position, the carriage and crimping-wheel drives are engaged for forward running while the crimping-head and clutch-control drives are disengaged and on return of the driving shaft to the mid position by the other stop, the carriage and crimping-wheel drives are disengaged and the crimping-head and clutch-control drives are successively engaged to cause, firstly, a movement of the crimping head and then axial displacement of the driving shaft in the opposite direction from the mid position to cause engagement of the crimping-wheel drive for forward running, the crimping head thereby laying crimped wire in a zig-zag path across the frame and around the pins on the frame. i

4. Apparatus according to claim 3,wherein the crimping-head drive includes a maltese-cross type mechanism, and the clutch-control drive includes a maltese-cross device operable consecutively by the pins on the pin wheel of said mechanism.

5. Apparatus according to claim 4, wherein the clutch control means includes a two-armed lever with one end connected to the driving shaft and the other end engaging a rotary cam adapted to swing the arm in one or other direction in accordance with the new direction to be taken by the carriage at the end of each operating stroke of the carriage.

6. Apparatus according to claim 5, wherein the pins on the frame are notched and are spring-urged downwards to a low position, and wedge means on the crimping head are engageable with the lower end of each pin in turn to raise the pin against spring action to a high position to receive in its notch the crimped wire from the head, each pin returning to low position on withdrawal of the wedge and the wire loop being retained on the pin by the notch.

7. Apparatus according to claim 6, wherein the toothed crimping wheels are disposed side-by-side on horizontal axes extending in the direction of movement of the head,

and discharge the crimped wire downwards between a pair of radiused guides around one or other of which the wire passes in accordance with the direction of movement of the carriage.

8. Apparatus according to claim 7, wherein the spaced crimping wheels are driven through a pair of meshing pinion wheels co-axial with the crimping wheels.

References Cited UNITED STATES PATENTS 761,204 5/1904 Carpenter 29611 2,526,327 10/1950 Carlson 219-203 2,731,713 1/1956 Schaefer 338286 CHARLES W. LANHAM, Primary Examiner.

RICHARD J. HERBST, Examiner.

L. A. LARSON, Assistant Examiner. 

